#include<bits/stdc++.h>
using namespace std;
int main()
{
	double xa, ya, za, xb, yb, zb, xc, yc, zc, r;
	cin>>xa>>ya>>za>>xb>>yb>>zb>>xc>>yc>>zc>>r;
	cout<<fixed<<setprecision(2)<<sqrt((xa-ya)*(xa-ya)+(xb-yb)*(xb-yb)+(xc-yc)*(xc-yc));
	return 0;
}

